Carrier aggregation with narrow bandwidth carriers

ABSTRACT

Performing carrier aggregation with narrow bandwidth carriers includes determining that a spectrum block allocated to a sector has a bandwidth that is narrower than a threshold bandwidth, wherein the threshold bandwidth is based on a size of a synchronization signal block (SSB), configuring the spectrum block as a narrow bandwidth carrier, performing carrier aggregation with the narrow bandwidth carrier as a secondary component carrier aggregated with the primary component carrier, and scheduling the SSB within the primary component carrier.

This patent application is a continuation of U.S. patent applicationSer. No. 16/791,032, filed on Feb. 14, 2020, which is incorporated byreference in its entirety for all purposes

TECHNICAL BACKGROUND

In order to allow for greater wireless network throughput andefficiency, wireless network operators can implement carrieraggregation, i.e. enabling wireless devices and access nodes tocommunicate using a combination of carriers known as component carriers.Component carriers utilize air-interface resources (such astime-frequency resource blocks) spanning different sets of frequencieswithin one or more frequency bands available to use within a wirelesssector. For example, a primary component carrier may utilize a first setof frequencies, and a secondary component carrier may utilize a secondset of frequencies. When two or more component carriers are in the samefrequency band, it is referred to as “intra-band carrier aggregation”whereas when the component carriers are parts of different frequencybands, it is referred to as “inter-band carrier aggregation.” Further,synchronization signals may be used to synchronize transmissions betweenthe network and the wireless devices. For example, in 5G New Radio (NR)wireless networks, a synchronization signal block utilizes a portion ofthe air-interface resources of one or more component carriers tosynchronize the transmissions. Wireless devices attached to the sectorusing carrier aggregation can refer to the synchronization signal blockto be able to receive transmissions via two or more component carriers.

There may be situations where differently-sized portions of an availablespectrum of air interface resources are allocated to a sector. Someportions may have a bandwidth (i.e. range of available frequencies) thatis too narrow to fit synchronization signals. Thus, the sector may beconfigured with a minimum possible bandwidth to be able to utilize acarrier for carrier aggregation. For instance, in 5G NR, there is aminimum channel bandwidth that is determined by the ability to fit asynchronization signal block. However, there may be certain spectrumallocations that have a bandwidth narrower than the size of thesynchronization signal block. Thus, these narrow portions of availableresources cannot currently be used for NR. While these narrow portionsare available for other narrowband transmissions (such as internet ofthings, etc.), they may otherwise be wasted due to their inability to beused for NR.

Overview

Exemplary embodiments described herein include systems, methods, andprocessing nodes for performing carrier aggregation with narrowbandwidth carriers. An exemplary method described herein for performingcarrier aggregation with narrow bandwidth carriers includes determiningthat a spectrum block allocated to a sector has a bandwidth that isnarrower than a threshold bandwidth, wherein the sector is configured todeploy a primary component carrier to which wireless devices within thesector are attached, configuring the spectrum block as a narrowbandwidth carrier, and performing carrier aggregation with the narrowbandwidth carrier as a secondary component carrier aggregated with theprimary component carrier.

An exemplary system described herein for performing carrier aggregationwith narrow bandwidth carriers includes a processing node and aprocessor coupled to the processing node. The processor is configured toperform operations including determining that a bandwidth of anavailable spectrum allocated to a wireless sector is unable toaccommodate synchronization signals, configuring the available spectrumas a secondary component carrier, and scheduling the synchronizationsignals within a primary component carrier of the wireless sector.

An exemplary processing node described herein for performing carrieraggregation with narrow bandwidth carriers is configured to performoperations comprising determining that a spectrum block allocated to asector has a bandwidth that is narrower than a threshold bandwidth,wherein the threshold bandwidth is based on a size of a synchronizationsignal block (SSB), configuring the spectrum block as a narrow bandwidthcarrier, performing carrier aggregation with the narrow bandwidthcarrier as a secondary component carrier aggregated with the primarycomponent carrier, and scheduling the SSB within the primary componentcarrier.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts an exemplary system for performing carrier aggregationwith narrow bandwidth carriers.

FIG. 2 depicts an exemplary processing node for performing carrieraggregation with narrow bandwidth carriers.

FIG. 3 depicts an exemplary access node for performing carrieraggregation with narrow bandwidth carriers.

FIG. 4 depicts an exemplary method for performing carrier aggregationwith narrow bandwidth carriers.

FIG. 5 depicts another exemplary method for performing carrieraggregation with narrow bandwidth carriers.

FIGS. 6A-6C depict exemplary narrow bandwidth carriers that areaggregated with primary component carriers.

DETAILED DESCRIPTION

Exemplary embodiments described herein include systems, methods, andprocessing nodes for creating narrow bandwidth carriers using availableresources within a sector. Allocated portions of radiofrequencyresources that are too narrow for synchronization signals can beconfigured as secondary carriers and aggregated with primary carriersthat have wider bandwidths. Since the synchronization signals (e.g. SSB)can be scheduled in the primary carriers, these narrow-bandwidthsecondary carriers can be made usable for any type of wireless devicecapable of carrier aggregation, in contrast to the present state of theart where these resources cannot be used as carriers, or can only beused for narrowband transmissions like IoT, etc. These and otherembodiments are further described herein and with reference to FIGS. 1-6.

FIG. 1 depicts an exemplary system 100 comprising a communicationnetwork 101, gateway 102, controller node 104, access node 110, andwireless devices 120. Access node 110 can be any network node configuredto provide communication between wireless devices 120 and communicationnetwork 101, including standard access nodes such as a macro-cell accessnode, base transceiver station, a radio base station, an eNodeB device,an enhanced eNodeB device, or the like. In an exemplary embodiment, amacro-cell access node can have a coverage area in the range ofapproximately five kilometers to thirty-five kilometers and an outputpower in the tens of watts. Alternatively, access node 110 may comprisea short range, low power, small-cell access node such as a microcellaccess node, a picocell access node, a femtocell access node, or a homeeNodeB device. In other embodiments, any other combination of accessnodes and wireless devices may be evident to those having ordinary skillin the art in light of this disclosure.

In operation, access node 110 (or any other network node communicablycoupled thereto) can be configured to perform carrier aggregation usingnarrow bandwidth carriers, by determining that a spectrum blockallocated to a sector of access node 110 has a bandwidth that isnarrower than a threshold bandwidth. For example, the access node can beconfigured to deploy a primary component carrier 121, to which wirelessdevices within the sector are attached. Primary component carrier 121can include frequency resources that have a bandwidth sufficient tosupport control signaling for primary component carrier 121, includingsynchronization signaling for carrier aggregation purposes. Further,there may be additional frequency resources allocated for use by accessnode 110, the additional frequency resources being sufficiently narrowthat they are unable to be used as an independent or primary componentcarrier, since they cannot accommodate the necessary signalingtransmissions. Thus, the available resources can be configured as anarrow bandwidth carrier 122, and a carrier aggregation mode isinitiated with the narrow bandwidth carrier 122 as a secondary componentcarrier aggregated with the primary component carrier 121.

Determining that the frequency resources of the available spectrum blockspan a sufficiently narrow bandwidth can be based on comparison with athreshold bandwidth. For example, the threshold bandwidth can includeany bandwidth that is wide enough to accommodate synchronization signalsfor carrier aggregation. If the additional frequency resources span abandwidth that is narrower than the threshold bandwidth, then they areconfigured as narrowband carrier 122 and aggregated with the primarycomponent carrier 121. Further, the synchronization signals for carrieraggregation are scheduled using the primary component carrier 121. Thesynchronizations signals enable wireless devices 120 to receive a datastream using both component carriers 121, 122. In an exemplaryembodiment, the synchronization signals comprise a synchronizationsignal block (SSB). The SSB can include synchronization signals alongwith a physical broadcast channel (PBCH) that is configured to transmita master information block (MIB). The synchronization signals caninclude primary synchronization signals (PSS) and secondarysynchronization signals (SSS). Further, the threshold bandwidth can bebased on a subcarrier spacing associated with the spectrum block (orfrequency band associated with the spectrum block). For example, if thesubcarrier spacing is 15 kHz, a corresponding SSB would require 3.6 MHz,and if the subcarrier spacing is 30 kHz, the corresponding SSB wouldrequire 7.2 MHz. Due to the numerology of 5G NR (as is known to thosehaving ordinary skill in the art), a 15 kHz subcarrier spacing isassociated with a minimum channel bandwidth of 5 MHz, and a 30 kHzsubcarrier spacing is associated with a minimum channel bandwidth of 10MHz. Thus, in exemplary embodiments, a minimum threshold bandwidth for a15 kHz subcarrier spacing carrier is 5 MHz, and a minimum thresholdbandwidth for a 30 kHz subcarrier spacing carrier is 10 MHz. In otherwords, the threshold bandwidth against which the available spectrumblock is compared varies based on a subcarrier spacing utilized by theaccess node and, correspondingly, a channel bandwidth associated withthe subcarrier spacing.

Further, the available spectrum block used to form secondary carrier 122uses the same frequency band as the primary component carrier 121. Thisis because the synchronization between component carriers becomesuncertain when carriers are in different frequency bands because theymay use different RF components, antennas and antenna wiring, etc. whichcan lead to different latencies. In other words, synchronization betweenintra-band carrier aggregation component carriers (within the samefrequency band) is simpler because the same RF chains and frequencysources can be used (compared with carriers spanning different frequencybands). Thus, when the narrow-bandwidth spectrum block utilizes the sameresources (within a single frequency band) as the primary componentcarrier 121, then the SSB can be scheduled within the primary componentcarrier 121 and aggregated with the secondary component carrier 122.Further, some network implementations may allow for inter-band carrieraggregation to share the SSB. Thus, the claimed embodiments do notpreclude the use of extra narrow-bandwidth frequency resources from adifferent frequency band, since the implementation of differentsignaling blocks may enable inter-band carrier aggregation using thenarrow bandwidth carrier.

Access node 110 can comprise a processor and associated circuitry toexecute or direct the execution of computer-readable instructions toperform operations such as those further described herein. Briefly,access node 110 can retrieve and execute software from storage, whichcan include a disk drive, a flash drive, memory circuitry, or some othermemory device, and which can be local or remotely accessible. Thesoftware comprises computer programs, firmware, or some other form ofmachine-readable instructions, and may include an operating system,utilities, drivers, network interfaces, applications, or some other typeof software, including combinations thereof. Further, access node 110can receive instructions and other input at a user interface. Accessnode 110 communicates with gateway node 102 and controller node 104 viacommunication link 106. Access node 110 may communicate with otheraccess nodes (not shown), using a wireless link or a wired link such asan X2 link. Components of exemplary access nodes 110 are furtherdescribed with reference to FIG. 3 .

Wireless devices 120 may be any device, system, combination of devices,or other such communication platform capable of communicating wirelesslywith access node 110 using one or more frequency bands deployedtherefrom. Each of wireless devices 120 may be, for example, a mobilephone, a wireless phone, a wireless modem, a personal digital assistant(PDA), a voice over internet protocol (VoIP) phone, a voice over packet(VOP) phone, or a soft phone, as well as other types of devices orsystems that can send and receive audio or data. Other types ofcommunication platforms are possible.

Communication network 101 can be a wired and/or wireless communicationnetwork, and can comprise processing nodes, routers, gateways, andphysical and/or wireless data links for carrying data among variousnetwork elements, including combinations thereof, and can include alocal area network a wide area network, and an internetwork (includingthe Internet). Communication network 101 can be capable of carryingdata, for example, to support voice, push-to-talk, broadcast video, anddata communications by wireless devices 120. Wireless network protocolscan comprise MBMS, code division multiple access (CDMA) 1×RTT, GlobalSystem for Mobile communications (GSM), Universal MobileTelecommunications System (UMTS), High-Speed Packet Access (HSPA),Evolution Data Optimized (EV-DO), EV-DO rev. A, Third GenerationPartnership Project Long Term Evolution (3GPP LTE), and WorldwideInteroperability for Microwave Access (WiMAX). Wired network protocolsthat may be utilized by communication network 101 comprise Ethernet,Fast Ethernet, Gigabit Ethernet, Local Talk (such as Carrier SenseMultiple Access with Collision Avoidance), Token Ring, Fiber DistributedData Interface (FDDI), and Asynchronous Transfer Mode (ATM).Communication network 101 can also comprise additional base stations,controller nodes, telephony switches, internet routers, networkgateways, computer systems, communication links, or some other type ofcommunication equipment, and combinations thereof.

Communication links 106, 107 can use various communication media, suchas air, space, metal, optical fiber, or some other signal propagationpath—including combinations thereof. Communication links 106, 107 can bewired or wireless and use various communication protocols such asInternet, Internet protocol (IP), local-area network (LAN), opticalnetworking, hybrid fiber coax (HFC), telephony, T1, or some othercommunication format—including combinations, improvements, or variationsthereof. Wireless communication links can be a radio frequency,microwave, infrared, or other similar signal, and can use a suitablecommunication protocol, for example, Global System for Mobiletelecommunications (GSM), Code Division Multiple Access (CDMA),Worldwide Interoperability for Microwave Access (WiMAX), or Long TermEvolution (LTE), or combinations thereof. Communication links 106, 107may include S1 communication links. Other wireless protocols can also beused. Communication links 106, 107 can be a direct link or might includevarious equipment, intermediate components, systems, and networks.Communication links 106, 107 may comprise many different signals sharingthe same link.

Gateway node 102 can be any network node configured to interface withother network nodes using various protocols. Gateway node 102 cancommunicate user data over system 100. Gateway node 102 can be astandalone computing device, computing system, or network component, andcan be accessible, for example, by a wired or wireless connection, orthrough an indirect connection such as through a computer network orcommunication network. For example, gateway node 102 can include aserving gateway (SGW) and/or a public data network gateway (PGW), etc.One of ordinary skill in the art would recognize that gateway node 102is not limited to any specific technology architecture, such as 5G NewRadio (NR) and can be used with any network architecture and/orprotocol.

Gateway node 102 can comprise a processor and associated circuitry toexecute or direct the execution of computer-readable instructions toobtain information. Gateway node 102 can retrieve and execute softwarefrom storage, which can include a disk drive, a flash drive, memorycircuitry, or some other memory device, and which can be local orremotely accessible. The software comprises computer programs, firmware,or some other form of machine-readable instructions, and may include anoperating system, utilities, drivers, network interfaces, applications,or some other type of software, including combinations thereof. Gatewaynode 102 can receive instructions and other input at a user interface.

Controller node 104 can be any network node configured to communicateinformation and/or control information over system 100. Controller node104 can be configured to transmit control information associated with ahandover procedure. Controller node 104 can be a standalone computingdevice, computing system, or network component, and can be accessible,for example, by a wired or wireless connection, or through an indirectconnection such as through a computer network or communication network.For example, controller node 104 can include a mobility managemententity (MME), a Home Subscriber Server (HSS), a Policy Control andCharging Rules Function (PCRF), an authentication, authorization, andaccounting (AAA) node, a rights management server (RMS), a subscriberprovisioning server (SPS), a policy server, etc. One of ordinary skillin the art would recognize that controller node 104 is not limited toany specific technology architecture, such as Long Term Evolution (LTE)and can be used with any network architecture and/or protocol.

Controller node 104 can comprise a processor and associated circuitry toexecute or direct the execution of computer-readable instructions toobtain information. Controller node 104 can retrieve and executesoftware from storage, which can include a disk drive, a flash drive,memory circuitry, or some other memory device, and which can be local orremotely accessible. In an exemplary embodiment, controller node 104includes a database 105 for storing information related to elementswithin system 100, such as subcarrier spacing information and associatedthreshold bandwidth sizes associated with access node 110, carrieraggregation capabilities of wireless devices 120, etc. This informationmay be requested by or shared with access node 110 via communicationlinks 106, 107, X2 connections, and so on. The software comprisescomputer programs, firmware, or some other form of machine-readableinstructions, and may include an operating system, utilities, drivers,network interfaces, applications, or some other type of software, andcombinations thereof. For example, a processing node within controllernode 104 can perform the operations described herein. Further,controller node 104 can receive instructions and other input at a userinterface.

Other network elements may be present in system 100 to facilitatecommunication but are omitted for clarity, such as base stations, basestation controllers, mobile switching centers, dispatch applicationprocessors, and location registers such as a home location register orvisitor location register. Furthermore, other network elements that areomitted for clarity may be present to facilitate communication, such asadditional processing nodes, routers, gateways, and physical and/orwireless data links for carrying data among the various networkelements, e.g. between access node 110 and communication network 101.

FIG. 2 depicts an exemplary processing node 200 for performing carrieraggregation with narrow bandwidth carriers. Processing node comprises acommunication interface 202, user interface 204, and processing system206 in communication with communication interface 202 and user interface204. Processing system 206 includes a central processing unit (CPU) 208,and a memory 210, which can comprise a disk drive, flash drive, memorycircuitry, or other memory device. Memory 210 can store computerprograms, firmware, or some other form of machine-readable instructions,including an operating system, utilities, drivers, network interfaces,applications, or some other type of software. Further, memory 210 canstore a software 212, which may be executed to perform the interferencemitigation operations described herein. Processing system 206 mayinclude other circuitry to retrieve and execute software 212 from memory210. Processing node 200 may further include other components such as apower management unit, a control interface unit, etc., which are omittedfor clarity. Communication interface 202 permits processing node 200 tocommunicate with other network elements. User interface 204 permits theconfiguration and control of the operation of processing node 200.

In an exemplary embodiment, software 212 can include instructions fordetermining that a spectrum block allocated to a sector has a bandwidththat is narrower than a threshold bandwidth, wherein the sector isconfigured to deploy a primary component carrier to which wirelessdevices within the sector are attached, configuring the spectrum blockas a narrow bandwidth carrier, and performing carrier aggregation withthe narrow bandwidth carrier as a secondary component carrier aggregatedwith the primary component carrier. In another exemplary embodiment,software 212 can include instructions for determining that a bandwidthof an available spectrum allocated to a wireless sector is unable toaccommodate synchronization signals, configuring the available spectrumas a secondary component carrier, and scheduling the synchronizationsignals within a primary component carrier of the wireless sector. Inanother exemplary embodiment, software 212 can include instructions fordetermining that a spectrum block allocated to a sector has a bandwidththat is narrower than a threshold bandwidth, wherein the thresholdbandwidth is based on a size of a synchronization signal block (SSB),configuring the spectrum block as a narrow bandwidth carrier, performingcarrier aggregation with the narrow bandwidth carrier as a secondarycomponent carrier aggregated with the primary component carrier, andscheduling the SSB within the primary component carrier.

FIG. 3 depicts an exemplary access node 310. Access node 310 maycomprise, for example, a macro-cell access node, such as access node 110described with reference to FIG. 1 . Access node 310 enablescommunication with network 301 via communication link 306, and isillustrated as comprising a processor 311, memory 312, transceiver 313,and antennae 314. Processor 311 executes instructions stored on memory312, while transceiver 313 and antennae 314 enable wirelesscommunication with wireless devices attached to one or more sectorsdeployed by access node 310. Further, antennae 314 may include an arrayof antennae that are configured to form beams within the sectors, employmultiple-input-multiple-output (MIMO), etc.

Further, instructions stored on memory 312 can include instructions fordetermining that a spectrum block allocated to a sector has a bandwidththat is narrower than a threshold bandwidth, wherein the sector isconfigured to deploy a primary component carrier to which wirelessdevices within the sector are attached, configuring the spectrum blockas a narrow bandwidth carrier, and performing carrier aggregation withthe narrow bandwidth carrier as a secondary component carrier aggregatedwith the primary component carrier. In another exemplary embodiment,memory 312 can include instructions for determining that a bandwidth ofan available spectrum allocated to a wireless sector is unable toaccommodate synchronization signals, configuring the available spectrumas a secondary component carrier, and scheduling the synchronizationsignals within a primary component carrier of the wireless sector. Inanother exemplary embodiment, memory 312 can include instructions fordetermining that a spectrum block allocated to a sector has a bandwidththat is narrower than a threshold bandwidth, wherein the thresholdbandwidth is based on a size of a synchronization signal block (SSB),configuring the spectrum block as a narrow bandwidth carrier, performingcarrier aggregation with the narrow bandwidth carrier as a secondarycomponent carrier aggregated with the primary component carrier, andscheduling the SSB within the primary component carrier.

FIG. 4 depicts an exemplary method for performing carrier aggregationwith narrow bandwidth carriers. The method of FIG. 4 may be implementedby an access node (such as access node 110, 310), by a controller node(such as controller node 104), by a processing node (such as processingnode 200), or by any other network node. Although FIG. 4 depicts stepsperformed in a particular order for purposes of illustration anddiscussion, the operations discussed herein are not limited to anyparticular order or arrangement. One skilled in the art, using thedisclosures provided herein, will appreciate that various steps of themethods can be omitted, rearranged, combined, and/or adapted in variousways.

At 410, it is determined that an available spectrum block has a narrowbandwidth. The available spectrum block may be assigned or allocated toan access node that is configured to deploy one or more carriers. Forexample, the access node can be configured to deploy a primary componentcarrier to which wireless devices within the sector are attached. Theprimary component carrier can include frequency resources that have abandwidth sufficient to support control signaling for the primarycomponent carrier or any additional carrier (such as one or moresecondary component carriers). Further, there may be additionalfrequency resources (i.e. available spectrum block) allocated for use bythe access node, the additional frequency resources being sufficientlynarrow that they are unable to be used as an independent or primarycomponent carrier, since they cannot accommodate the necessary signalingtransmissions. Determining that the frequency resources of the availablespectrum block span a sufficiently narrow bandwidth can be based oncomparison with a threshold bandwidth. For example, the thresholdbandwidth can include any bandwidth that is wide enough to accommodatesynchronization signals for carrier aggregation. In an exemplaryembodiment, the synchronization signals comprise a synchronizationsignal block (SSB). The SSB can include synchronization signals alongwith a physical broadcast channel (PBCH) that is configured to transmita master information block (MIB). The synchronization signals caninclude primary synchronization signals (PSS) and secondarysynchronization signals (SSS). Further, the threshold bandwidth can bebased on a subcarrier spacing associated with the spectrum block (orfrequency band associated with the spectrum block). For example, if thesubcarrier spacing is 15 kHz, a corresponding SSB would require 3.6 MHzso the threshold is 5 MHz, and if the subcarrier spacing is 30 kHz, thecorresponding SSB would require 7.2 MHz and the threshold bandwidth is10 MHz. Due to the numerology of 5G NR (as is known to those havingordinary skill in the art), a 15 kHz subcarrier spacing is associatedwith a channel bandwidth of at least 5 MHz, and a 30 kHz subcarrierspacing is associated with a channel bandwidth of at least 10 MHz. Thus,in exemplary embodiments, a minimum threshold bandwidth for a 15 kHzsubcarrier spacing carrier is 5 MHz, and a minimum threshold bandwidthfor a 30 kHz subcarrier spacing carrier is 10 MHz. In other words, thethreshold bandwidth against which the available spectrum block iscompared varies based on a subcarrier spacing utilized by the accessnode and, correspondingly, a channel bandwidth associated with thesubcarrier spacing.

At 420, resources within the available spectrum block are configured asa narrow bandwidth carrier. For example, upon determining that theadditional frequency resources span a bandwidth that is narrower thanthe threshold bandwidth, then they are configured as a narrowbandcarrier. At 430, carrier aggregation is performed with the narrowbandwidth carrier as the secondary component carrier aggregated with theprimary component carrier. and aggregated with the primary componentcarrier. Further, the synchronization signals for carrier aggregationare scheduled using the primary component carrier. The synchronizationssignals enable wireless devices to receive a data stream using bothcomponent carriers. Further, the available spectrum block used to formthe secondary carrier uses the same frequency band as the primarycomponent carrier. This is because the synchronization between componentcarriers becomes uncertain when the carriers are in different frequencybands because they may use different RF components, antennae, antennawiring, etc., which can lead to different latencies. In other words,synchronization between intra-band carrier aggregation componentcarriers in the same frequency band is simpler because the same RFchains and frequency sources can be used (compared with carriersspanning different frequency bands). Thus, when the narrow-bandwidthspectrum block utilizes the same resources (within a single frequencyband) as the primary component carrier, then the SSB can be scheduledwithin the primary component carrier and aggregated with the secondarycomponent carrier. Certain network implementations may allow forinter-band carrier aggregation to share the SSB. Thus, the claimedembodiments do not preclude the use of extra narrow-bandwidth frequencyresources from a different frequency band, since the implementation ofdifferent signaling blocks and associated threshold bandwidths mayenable inter-band carrier aggregation using the narrow bandwidthcarrier.

FIG. 5 depicts another exemplary method for performing carrieraggregation with narrow bandwidth carriers. The method of FIG. 5 may beimplemented by an access node (such as access node 110, 310), by acontroller node (such as controller node 104), by a processing node(such as processing node 200), or by any other network node. AlthoughFIG. 5 depicts steps performed in a particular order for purposes ofillustration and discussion, the operations discussed herein are notlimited to any particular order or arrangement. One skilled in the art,using the disclosures provided herein, will appreciate that varioussteps of the methods can be omitted, rearranged, combined, and/oradapted in various ways.

At 510, a bandwidth is obtained for available frequency resources of aspectrum assigned to a sector. The available frequency resources may beassigned or allocated to an access node that is configured to deploy oneor more carriers. For example, the access node can be configured todeploy a primary component carrier to which wireless devices within thesector are attached. The primary component carrier can include frequencyresources that have a bandwidth sufficient to support control signalingfor the primary component carrier or any additional carrier (such as oneor more secondary component carriers). Further, there may be additionalfrequency resources (i.e. available spectrum block) allocated for use bythe access node, the additional frequency resources being sufficientlynarrow that they are unable to be used as an independent or primarycomponent carrier, since they cannot accommodate the necessary signalingtransmissions.

At 520, the bandwidth is compared to a threshold to determine whether ornot the bandwidth can accommodate synchronization signals, such as anSSB. For example, the threshold bandwidth can include any bandwidth thatis wide enough to accommodate synchronization signals for carrieraggregation. In an exemplary embodiment, the synchronization signalscomprise a synchronization signal block (SSB). The SSB can includesynchronization signals along with a physical broadcast channel (PBCH)that is configured to transmit a master information block (MIB). Thesynchronization signals can include primary synchronization signals(PSS) and secondary synchronization signals (SSS). Further, thethreshold bandwidth can be based on a subcarrier spacing associated withthe spectrum block (or frequency band associated with the spectrumblock). For example, if the subcarrier spacing is 15 kHz, acorresponding SSB would require 3.6 MHz, and if the subcarrier spacingis 30 kHz, the corresponding SSB would require 7.2 MHz. Due to thenumerology of 5G NR (as is known to those having ordinary skill in theart), a 15 kHz subcarrier spacing is associated with a minimum channelbandwidth of 5 MHz, and a 30 kHz subcarrier spacing is associated with aminimum channel bandwidth of 10 MHz. Thus, in exemplary embodiments, aminimum threshold bandwidth for a 15 kHz subcarrier spacing carrier is 5MHz, and a minimum threshold bandwidth for a 30 kHz subcarrier spacingcarrier is 10 MHz. In other words, the threshold bandwidth against whichthe available spectrum block is compared varies based on a subcarrierspacing utilized by the access node and, correspondingly, a channelbandwidth associated with the subcarrier spacing.

At 530, upon determining that the bandwidth does not meet the threshold,resources within the available spectrum block are configured as a narrowbandwidth carrier and, at 540, carrier aggregation is performed with thenarrow bandwidth carrier as the secondary component carrier aggregatedwith the primary component carrier. and aggregated with the primarycomponent carrier. Further, the synchronization signals for carrieraggregation are scheduled using the primary component carrier. Thesynchronizations signals enable wireless devices to receive a datastream using both component carriers. Further, if at 520 it isdetermined that the available spectrum has a bandwidth that meets one ormore thresholds, then the available spectrum may be used as a primarycomponent carrier, or any other carrier that is not a narrow bandwidthcarrier.

FIGS. 6A-6C depict exemplary narrow bandwidth carriers that areaggregated with primary component carriers. With reference to FIG. 6A,an access node may be configured to utilize a primary component carrier(PCC) 601. The bandwidth of PCC 601 is sufficiently wide to accommodatean SSB 611. Further, an available spectrum block may be configured as asecondary component carrier (SCC) 602, based on determining that abandwidth of the available spectrum block is less than the thresholdsize for accommodating SSB 611. SCC 602 can be aggregated with PCC 601,with the synchronization being managed by SSB 611. With reference toFIG. 6B, the access node can be configured to deploy at least one PCC601, and has available resources that are sufficiently wide to configureas another PCC 603 (which may also be configured as an SCC). Both PCC601 and PCC/SCC 603 have a bandwidth wide enough to accommodate SSBs611/613. Further, an available spectrum block may be configured as asecondary component carrier (SCC) 602, based on determining that abandwidth of the available spectrum block is less than the thresholdsize for accommodating SSBs 611/613. SCC 602 can be aggregated with PCC601 and/or PCC/SCC 603, with the synchronization being managed by SSBs611/613.

The carriers of FIGS. 6A and 6B are illustrated as being part of thesame frequency band (band1). With reference to FIG. 6C, two differentfrequency bands band1 and band2 may be assigned to or allocated for useby an access node. For example, the access node may be configured toutilize a primary component carrier (PCC) 601 having a bandwidthsufficiently wide to accommodate an SSB 611. Further, an availablespectrum block (within band1) may be configured as a secondary componentcarrier (SCC) 602, based on determining that a bandwidth of theavailable spectrum block is less than the threshold size foraccommodating SSB 611. SCC 602 can be aggregated with PCC 601, with thesynchronization being managed by SSB 611. Similarly, the access node maybe configured to utilize a PCC 604 (within band2) having a bandwidthsufficiently wide to accommodate an SSB 614. Further, an availablespectrum block (within band2) may be configured as a secondary componentcarrier (SCC) 605, based on determining that a bandwidth of theavailable spectrum block is less than the threshold size foraccommodating SSB 614. SCC 605 can be aggregated with PCC 604, with thesynchronization being managed by SSB 614.

Although the narrow-bandwidth carriers of FIGS. 6A-6C are illustrated asbeing aggregated with PCCs of the same frequency band (intra-bandcarrier aggregation), the available spectrum block may contain resourcesfrom a different frequency band in which case since the signaling may bemore complex. The subject disclosure does not preclude the use of extranarrow-bandwidth frequency resources from a different frequency band,since the implementation of different signaling blocks and associatedthreshold bandwidths may enable inter-band carrier aggregation using thenarrow bandwidth carrier.

The exemplary systems and methods described herein can be performedunder the control of a processing system executing computer-readablecodes embodied on a computer-readable recording medium or communicationsignals transmitted through a transitory medium. The computer-readablerecording medium is any data storage device that can store data readableby a processing system, and includes both volatile and nonvolatilemedia, removable and non-removable media, and contemplates mediareadable by a database, a computer, and various other network devices.

Examples of the computer-readable recording medium include, but are notlimited to, read-only memory (ROM), random-access memory (RAM), erasableelectrically programmable ROM (EEPROM), flash memory or other memorytechnology, holographic media or other optical disc storage, magneticstorage including magnetic tape and magnetic disk, and solid statestorage devices. The computer-readable recording medium can also bedistributed over network-coupled computer systems so that thecomputer-readable code is stored and executed in a distributed fashion.The communication signals transmitted through a transitory medium mayinclude, for example, modulated signals transmitted through wired orwireless transmission paths.

The above description and associated figures teach the best mode of theinvention. The following claims specify the scope of the invention. Notethat some aspects of the best mode may not fall within the scope of theinvention as specified by the claims. Those skilled in the art willappreciate that the features described above can be combined in variousways to form multiple variations of the invention. As a result, theinvention is not limited to the specific embodiments described above,but only by the following claims and their equivalents.

What is claimed is:
 1. A method for performing carrier aggregation, themethod comprising: determining that a spectrum block allocated to asector has a bandwidth that is narrower than a threshold bandwidth,wherein the threshold bandwidth is based on a subcarrier spacingassociated with the spectrum block, wherein the sector is configured todeploy a primary component carrier; configuring the spectrum block as anarrow bandwidth carrier; and performing carrier aggregation with thenarrow bandwidth carrier as a secondary component carrier aggregatedwith the primary component carrier.
 2. The method of claim 1, whereinthe primary component carrier comprises a bandwidth that is wide enoughto accommodate synchronization signals for carrier aggregation.
 3. Themethod of claim 2, wherein the synchronization signals comprise asynchronization signal block (SSB).
 4. The method of claim 2, furthercomprising scheduling the synchronization signals for carrieraggregation using the primary component carrier.
 5. The method of claim1, wherein the threshold bandwidth is lower than a minimum bandwidththat is wide enough to accommodate synchronization signals for carrieraggregation.
 6. The method of claim 1, wherein the subcarrier spacing is2^(n)×15 kHz and the threshold bandwidth is at least 2^(n)×5 MHz,wherein n is a positive integer or zero.
 7. The method of claim 1,wherein the spectrum block and the primary component carrier utilizeresources within different frequency bands.
 8. The method of claim 1,wherein the spectrum block and the primary component carrier utilizeresources within a single frequency band.
 9. A system for performingcarrier aggregation, the system comprising: a processing node; and aprocessor communicably coupled to the processing node, the processorbeing configured to perform operations comprising: determining that abandwidth of an available spectrum allocated to a wireless sector isunable to accommodate synchronization signals based on a subcarrierspacing associated with the available spectrum; configuring theavailable spectrum as a narrow bandwidth carrier; and aggregating thenarrow bandwidth carrier as a secondary component carrier with a primarycomponent carrier of the wireless sector.
 10. The system of claim 9,wherein the primary component carrier comprises a bandwidth that is wideenough to accommodate the synchronization signals.
 11. The system ofclaim 9, the operations further comprising scheduling thesynchronization signals within the primary component carrier.
 12. Thesystem of claim 9, wherein determining that the bandwidth of theavailable spectrum is unable to accommodate the synchronization signalscomprises determining that the bandwidth of the available spectrum issmaller than a threshold bandwidth.
 13. The system of claim 12, whereinthe threshold bandwidth is based on a minimum bandwidth required by thesynchronization signals.
 14. The system of claim 12, wherein thesubcarrier spacing is 2^(n)×15 kHz and the threshold bandwidth is atleast 2^(n)×5 MHz, wherein n is a positive integer or zero.
 15. Aprocessing node for performing carrier aggregation with narrow bandwidthcarriers, the processing node being configured to perform operationscomprising: determining that a first spectrum block allocated to asector has a bandwidth that is narrower than a threshold bandwidth,wherein the threshold bandwidth is based on a numerology associated withthe first spectrum block; configuring the first spectrum block as afirst narrow bandwidth carrier; performing carrier aggregation with thefirst narrow bandwidth carrier as a first secondary component carrieraggregated with a first primary component carrier; and scheduling asynchronization signal block (SSB) within the first primary componentcarrier.
 16. The processing node of claim 15, wherein the thresholdbandwidth is based on a subcarrier spacing associated with thenumerology.
 17. The processing node of claim 16, wherein the subcarrierspacing is 2^(n)×15 kHz and the threshold bandwidth is at least 2^(n)×5MHz, wherein n is a positive integer or zero.
 18. The processing node ofclaim 15, wherein the first spectrum block and the first primarycomponent carrier utilize resources within a single frequency band. 19.The processing node of claim 18, further comprising: determining that asecond spectrum block allocated to the sector has a bandwidth that isnarrower than the threshold bandwidth, wherein the second spectrum blockutilizes resources in a different frequency band than the first spectrumblock and the first primary component carrier; configuring the secondspectrum block as a second narrow bandwidth carrier; and performingcarrier aggregation with the second narrow bandwidth carrier as a secondcomponent carrier aggregated with a second primary component carrier,wherein the second primary component carrier utilizes resources in adifferent frequency band than the first spectrum block and the firstprimary component carrier.
 20. The processing node of claim 15, whereinthe first spectrum block and the first primary component carrier utilizeresources within different frequency bands.